U.S. patent number 4,445,513 [Application Number 06/383,169] was granted by the patent office on 1984-05-01 for device for straightening spinal column.
This patent grant is currently assigned to Max Bernhard Ulrich. Invention is credited to Gys H. Slot, Bernhard Ulrich.
United States Patent |
4,445,513 |
Ulrich , et al. |
May 1, 1984 |
Device for straightening spinal column
Abstract
A device for straightening a spinal column having a succession
of vertebrae extending along a nonstraight line lying generally in
a plane has an elongated bar lying generally in the plane of the
line and having a pair of relatively longitudinally displaceable
bar parts in turn having respective bar ends. A pair of connectors
of the bar ends are secured to respective vertebrae of the
succession. Respective pivots between the connectors and the
respective ends define therebetween respective generally parallel
axes transverse to the plane. A main abutment movable along and
flexible on one of the parts and longitudinally engageable with the
other of the parts serves for limiting relative longitudinal
displacement of the parts toward each other. Thus the main abutment
can be moved along the one part to increase the spacing between the
ends and thereby can straighten the succession of vertebrae between
the connectors.
Inventors: |
Ulrich; Bernhard (Ulm,
DE), Slot; Gys H. (Nijmegen, NL) |
Assignee: |
Ulrich; Max Bernhard (Ulm,
DE)
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Family
ID: |
6133424 |
Appl.
No.: |
06/383,169 |
Filed: |
May 28, 1982 |
Foreign Application Priority Data
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May 29, 1981 [DE] |
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3121271 |
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Current U.S.
Class: |
606/86A; 606/105;
606/256; 606/258 |
Current CPC
Class: |
A61B
17/7008 (20130101); A61B 17/7079 (20130101); A61B
17/7014 (20130101); A61B 17/809 (20130101) |
Current International
Class: |
A61B
17/88 (20060101); A61B 17/70 (20060101); A61B
17/68 (20060101); A61B 17/80 (20060101); A61F
005/00 () |
Field of
Search: |
;128/69,92R,92B,92E,75,78 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2649042 |
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Sep 1978 |
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DE |
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485739 |
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Dec 1975 |
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SU |
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Primary Examiner: Frinks; Ronald L.
Attorney, Agent or Firm: Ross; Karl F. Dubno; Herbert
Claims
We claim:
1. A device for straightening a spinal column having a succession
of vertebrae extending along a nonstraight line lying generally in
a plane, said device comprising:
an elongated bar lying generally in said plane of said line and
having a pair of relatively longitudinally displaceable bar parts
in turn having respective bar ends;
a pair of connectors at said ends and each having two generally
penpendicular flanges one of which is provided with projecting
points and is shaped to fit onto a vertebra end surface with said
points engaged therein and the other of which is shaped to fit
simultaneously onto a vertebra side surface and is provided with
the respective pivot;
means for securing said connectors to respective vertebrae of said
succession;
respective pivots between said connectors and the respective ends
and defining therebetween respective generally parallel axes
transverse to said plane; and
means including a main abutment movable along and fixable on one of
said parts and longitudinally engageable with the other of said
parts for limiting relative longitudinal displacement of said parts
toward each other, whereby said main abutment can be moved along
said one part to increase the spacing between said ends and thereby
can straighten the succession of vertebrae between said
connectors.
2. The device defined in claim 1 wherein each of said other flanges
is provided with at least one tab carrying an axle pin constituting
the respective pivot and traversing the respective end.
3. The device defined in claim 4 wherein said axle pins are
generally parallel to the respective other flanges.
4. The device defined in claim 1 wherein said parts telescope in
each other, one being a rod and the other a tube.
5. The device defined in claim 4 wherein said main abutment is
carried on said rod and engageable with said tube.
6. The device defined in claim 5 wherein said rod is threaded and
said main abutment is a nut threaded on said rod.
7. The device defined in claim 1 wherein said parts telescope and
include a threaded rod and a tube, said main abutment being a nut
threaded on said rod and engageable longitudinally with said tube,
said tube being formed to one side of said main abutment with a
secondary abutment directed toward said main abutment and said rod
being formed to the other side of said main abutment with another
secondary abutment, said device further comprising a plier-type
spreader tool engageable with said secondary abutments and
actuatable to push same apart, whereby said main abutment can be
screwed down to a new position against said tube.
8. A device for straightening a spinal column having a succession
of vertebrae extending along a nonstraight line lying generally in
a plane, said device comprising:
an elongated bar lying generally in said plane of said line and
having a pair of relatively longitudinally displaceable bar parts
in turn having respective bar ends, said bar further having at
least one generally cylindrical extremity, the respective end being
fitted thereinto for rotation about the longitudinl bar axis, said
end part of said cylindrical extremity including
a filler part having a socket fitted over said extremity and a
cylindrical extremity identical to that of said bar, and
a pivot part connected to the respective pivot and having a socket
fitted over the extremity of said filler part;
a pair of connectors at said ends;
means for securing said connectors to respective vertebrae of said
succession;
respective pivots between said connectors and the respective ends
and defining therebetween respective generally parallel axes
transverse to said plane; and
means including a main abutment movable along and fixable on one of
said parts and longitudinally engageable with the other of said
parts for limiting relative longitudinal displacement of said parts
toward each other, whereby said main abutment can be moved along
said one part to increase the spacing between said ends and thereby
can straighten the succession of vertebrae between said
connectors.
9. A device for straightening a spinal column having a succession
of vertebrae extending along a nonstraight line lying generally in
a plane, said device comprising:
an elongated bar lying generally in said plane of said line and
having a threaded rod and a tube telescoped and longitudinally
displaceable thereon, the rod and tube having respective bar
ends;
a pair of connectors at said ends;
means for securing said connectors to respective vertebrae of said
succession;
respective pivots between said connectors and the respective ends
and defining therebetween respective generally parallel axes
transverse to said plane;
means including a main-abutment nut threaded on and movable along
said rod and longitudinally engageable with said tube for limiting
relative longitudinal displacement of said tube and rod toward each
other, said tube being formed to one side of said nut with a
secondary abutment directed toward said nut and said rod being
formed to the other side of said nut with another secondary
abutment, whereby said main abutment can be moved along said rod to
increase the spacing between said ends and thereby can straighten
the succession of vertebrae between said connectors; and
a plier-type spreader tool engageable with said secondary abutments
and actuatable to push same apart, whereby said nut can be screwed
down to a new position against said tube.
10. The device defined in claim 9 wherein said bar has at least one
generally cylindrical extremity and the respective end is fitted
thereof for rotation about the longitudinal axis of the bar.
11. The device defined in claim 9, further comprising:
two anchors securable to side surfaces respective vertebrae of said
succession; and
a rigid spacer rod having opposite ends secured in said anchors and
extending straightly therebetween.
12. The device defined in claim 11 wherein said anchors are screws
having heads forming seats for said opposite ends.
Description
FIELD OF THE INVENTION
The present invention relates to a device for straightening a
spinal column having a succession of vertebra lying in a
nonstraight line. More particularly this invention relates to an
orthopedic surgical tool for straightening and splinting a spinal
column deformed by lordosis, kyphosis, or scoliosis.
BACKGROUND OF THE INVENTION
Curvature of the spine, whether dorsally convex from kyphosis,
forwardly or ventrally convex from scoliosis, or laterally curved
from lordosis, can be corrected by an orthopedic surgical technique
of simply forcing the curved succession of vertebrae into a
straight position and then holding them forcibly in this position.
When the ligaments readjust the splinting holding the vetebrae in
the new position can be removed and these vertebrae will normally
remain in the newly set position.
U.S. Pat. Nos. 2,774,350 of C.S. Cleveland describes an arrangement
wherein the spinal processes of the vertebrae being straightened
are exposed in a long surgical incision and are secured to
respective clips carried on respective threaded rods. The other
ends of these rods pass through guides slidable along a main
threaded rod lying in the plane of the spinal curvature. The
clip-carrying rods have nuts flanking the respective guides so the
distance from the main rod to each clip can be changed and set. The
distance between adjacent guides on the main rod can be adjusted
similarly by means of pairs of nuts flanking the guides. Thus the
vertebrae can be pulled into a straight line by shortening the
distance between the main rod and the middle clips and
simultaneously increasing the distance between guides along the
main rod.
Such as arrangement is quite bulky and takes enormous pains to
operate, as the surgeon must tighten the various nuts one at a time
and only a slight increment each time to create the desired shape,
so that the straightening operation is extremely laborious. After
the spine is straightened, the entire device must be left
projecting through the long incision until the new position has
set, that is until the ligaments that hitherto were on the inside
of the curve have stretched and those on the outside of the curve
have shrunk to their new equal sizes. Obviously these disadvantages
make this device less than wholly satisfactory for the surgeon and
patient.
It is also known from German Pat. No. 2,649,042 based on an
application filed Oct. 28, 1976 by M. B. Ulrich to provide an
implantable splint that constitutes part of the device that
actually does the straightening, and that can be left in the
patient after the spine is straightened to keep the hitherto curved
portion of the spine straight, although it is noted of course that
the term "straight" is relative only as virtually all parts of the
spine are at least gently curved. This splint has a threaded rod
that is bendable and extends through a succession of anchors
secured to the vertebrae to be straightened. Another implement is
employed to initially straighten the succession of vertebrae, with
concomitant adjustment of pairs of nuts on the threaded rod that
flank the respective anchors. Once the desired straightness is
established, the pairs of nuts are tightened against the respective
anchors to lock in the set position. This system allows the patient
to be closed up after surgery, but still entails considerable work
for the initial straightening operation. In addition the rod or
rods, which must be flexible in order to follow the original curved
line of the anchors, cannot be very rigid, so that occasionally the
spine will at least partially revert to its initial nonstraight
position.
It is also known to use so-called distraction rods or bars to
straighten curved portions of the spine and subsequently to splint
the straightened portion in position. Such rods have hooks on their
ends that engage over lateral sides of the bony processes of the
vertebrae. Normally they are secured in place once the appropriate
portion of the spine has been straightened, and are left implanted.
Such devices have the disadvantage that they rarely match the exact
anatomical shape. In addition, when made adjustable they
occasionally come disconnected, requiring corrective surgery to
reconnect them.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide an
improved device for straightening and splinting a spinal
column.
Another object is the provision of such a device for straightening
and splinting a spinal column which overcomes the above-given
disadvantages.
A further object is to provide such a device which allows the
surgeon to rapidly and easily effect the required straightening,
which term is here used to cover any lessening of curvature.
Yet another object is to provide such a device which has simple and
rigid splints that can be implanted and that will surely hold the
straightened spine portion in the desired shape.
SUMMARY OF THE INVENTION
These objects are attained according to the instant invention in a
device for straightening a spinal column having a succession of
vertebrae extending along a nonstraight line lying generally in a
plane. This device has an elongated bar lying generally in the
plane of the line and having a pair of relatively longitudinally
displaceable bar parts in turn having respective bar ends. A pair
of connectors at the bar ends are secured to respective vertebrae
of the succession. Respective pivots between the connectors and the
respective ends define therebetween respective generally parallel
axes transverse to the plane. Means including a main abutment
movable along and fixable on one of the parts and longitudinally
engageable with the other of the parts serves for limiting relative
longitudinal displacement of the parts toward each other. Thus the
main abutment can be moved along the one part to increase the
spacing between the ends and thereby can straighten the succession
of vertebrae between the connectors.
This arrangement can therefore be used relatively easily to
establish the desired spacing between the two outermost vertebrae
of the succession. Due to the pivotal connection it is possible to
exert a considerable straightening force on these outer vertebrae
without damage to them. Furthermore the straightening force can be
exactly and easily dosed. Nonetheless the straightening can be
carried out rapidly.
The device according to the invention further has end parts which
each have two generally perpendicular flanges one of which is
provided with projecting points and is shaped to fit onto a
vertebra end surface with the points engaged therein and the other
of which is shaped to fit simultaneously onto a vertebra side
surface and is provided with the respective pivot. In this manner
the ends are solidly mounted to these vertebrae so that
considerable force can be brought to bear without breaking them
out. Normally according to this invention each of the other flanges
is provided with at least one tab carrying an axle pin constituting
the respective pivot and traversing the respective end. These axle
pins are generally parallel to the respective other flanges. Such
end parts therefore sit very solidly on the respective
vertebrae.
According to another feature of the instant invention one of the
parts is a rod and the other a tube, and they telescope together.
The main abutment is carried on the rod and is engageable with the
tube. More specifically the rod is threaded and the main abutment
is a nut threaded on the rod. Such a system makes it very simple to
control the straightening force finely and steplessly.
In such a device the tube is formed to one side of the main
abutment with a secondary abutment directed toward the main
abutment and the rod is formed to the other side of the main
abutment with another secondary abutment. It is possible to adjust
the length of such a device by means of a plier-type spreader tool
engageable with the secondary abutments and actuatable to push same
apart. Thus the pliers longitudinally separate the tube and rod,
whereupon the nut is screwed along to lock in the set spacing, and
so on.
It is also possible according to this invention for the bar to have
at least one generally cylindrical extremity and for the respective
end to be fitted therein for rotation about the longitudinal axis
of the bar. More specifically the end part of the cylindrical
extremity includes a filler part having a socket fitted over the
extremity and a cylindrical extremity identical to that of the bar,
and a pivot part connected to the respective pivot and having a
socket fitted over the extremity of the filler part. With this
system the distractor/straightener can be spread as described above
with the pliers until it is at the limit of its extensibility. Then
the ends are propped apart temporarily, the main abutment is
screwed back down the rod so that the one extremity can pull out of
the filler part, and another filler part is fitted in. Virtually
any reasonable length can be constructed in this manner. In
addition the use of the plier-type spreader plus the easy to rotate
main abutment makes such a procedure quite easy and rapid.
The invention also comprises a splint having two anchors securable
to side surfaces of respective vertebrae of the succession and a
rigid spacer rod having opposite ends secured in the anchors and
extending straightly therebetween. According to this invention the
anchors are screws having heads forming seats for the opposite
ends.
DESCRIPTION OF THE DRAWING
The above and other features and advantages will become more
readily apparent from the following, reference being made to the
accompanying drawing in which:
FIG. 1 is a side view partly in axial section through a
straightening device according to this invention;
FIG. 2 is a top view of the device of FIG. 1;
FIG. 3 is a side view illustrating use of the device according to
this invention;
FIG. 4 is a view like FIG. 3 but showing the device after the spine
portion has been straightened and splints have been mounted in
place.; and
FIG. 5 is a side view of a detail of the splint of FIG. 4.
SPECIFIC DESCRIPTION
As seen in FIGS. 1-3 the device according to this invention
basically comprise a distraction bar 1 having connectors 2 that are
attached to the end vertebrae 3 of a succession of vertebrae 3, 3.1
extending along a curved line 7 defining a plane P (FIG. 2 only) on
which the bar 1 lies and which in FIGS. 1 and 3 is the plane of the
drawing. The ends of the bar are connected to the connectors 2 by
parallel pivot pins 4 perpendicular to the plane P.
The bar 1 is formed of a tube 1.1 and a rod 1.2 telescoping in this
tube 1.1 and formed with a screwthread 9. The cross section of the
passage of the tube 1.1 and that of the rod 1.2 can be nonround and
complementary to prevent the two from rotating relative to each
other. Simply making the two parts cylindrical with a flat along
one side of the rod 1.2 and a corresponding indent in the tube
would be sufficient to rotationally link the two together. The tube
1.1 is formed adjacents its one end with an annular ridge or
abutment 5.1. A ring 5.2 is threaded on the rod 1.2 adjacent this
abutment 5.1, and another ring 6 is threaded on the rod 1.2 between
the two abutments 5.1 and 5.2.
Each connector has a flange 2.1 that lies on the side surface of
the respective vertebra and another flange 2.2 perpendicular
thereto and provided with points or spikes 2.3 that can poke into
the end surface of a vertebra 3 against which the flange 2.2 lies.
The side flange 2.1 is formed with two cheeks or tabs 2.4 between
which the respective axle pin 4 is fixed and extends. Eyes 8 on the
ends of the bar 1 are traversed by these pins 4.
The upper end of the bar 1 is formed with a cylindrical projection
or extremity 10 that fits in a socket or seat 11.1 of a filler part
13 that in turn has a cylindrical projection or extremity 10.1
identical to the extremity 10. This extremity 10.1 fits in a socket
11 formed on the eye 8, which socket 11 is identical to the socket
11.1. The filler 13 and eye 8 are formed with annular abutment
rings or ridges 14 spaced apart along the axis A of the bar 1.
In use as seen in FIG. 3 the flanges 2.2 are fitted to the upper
and lower vertebrae 3, with the flanges 2.1 lying on the side
surface at the inside of the curve to be corrected. The tabs 2.4
are coplanar and normally the eyes 8 are carried right on the
connectors 2 with the bar 1 separate.
This bar 1 is then installed with the abutment ring 5.1 and ring 6
screwed virtually to the end of the rod 1.2, and enough fillers or
spacers 13 to fill the distance between the two eyes 8. The
extremity 10 or 10.1 is fitted to the appropriate socket 11 or 11.1
and the end of the rod 9 is similarly aligned with the
corresponding hole 11.2 of the lower eye 8. The abutment ring 6 is
then screwed out until it is snug against the end of the tube 1.1
and the entire bar 1 is stiff between the connectors 2, and the
other abutment ring 5.2 is drawn up near but not against the ring
6.
Then as shown in FIG. 3 a pliers tool 15 having a pair of jaws 15.1
and a pair of handles 15.2 is fitted to the bar 1, with the jaws
15.1 bearing on the confronting faces of the abutment 5.1 and 5.2.
The surgeon squeezes the handles 15.2 together to force the
abutments apart and lengthen the bar 1. Before releasing pressure
on the handles 15.2 the abutment 6 is screwed along the screwthread
9 to lock in the set position. The other abutment 5.2 is then moved
up toward the abutment 5.1 and the procedure is repeated.
At any time the entire assembly can be temporarily braced while the
rings 5.2 and 6 are screwed back down the rod 1.2 and a filler 13
is inserted, to increase the overall length an increment.
Thereafter the adjustment operation described above is
repeated.
When as seen in FIG. 4 the succession of vertebrae 3, 3.1 is
straightened, with the line 7 much straighter than in FIG. 3,
implant splints are installed which each comprises a rod 20 and a
pair of anchors 21. These anchors 21 are formed as seen in FIG. 5
like self-tapping screws, each having a threaded shank 21.1 and a
head 21.2 formed with a notch 23.3 having a recessed seat 21.4. The
rod 20 has small-diameter threaded ends 20.1 that are threaded into
nuts 22 each having a collar 22.1 received in the respective seat
recess 21.4.
The anchors are screwed into the spongy bone of the vertebrae 3.1
immediately adjacent those to which the connectors 2 are secured.
Then a rod 20 of appropriate length is fitted to the anchors 21 and
locked in place with the nuts 22. These rods 20, one of which may
be applied to each side of the spinal column, are extremely rigid
and will effectively inhibit the spine from returning to the shape
it had before distraction.
Once the splints 20-22 are in place the bar 1 is shortened and
removed and the connectors 2 are pulled loose and also removed. The
incision can be closed.
The system according to the instant invention therefore is quite
simple, but will allow the surgeon to rapidly and easily straighten
a spine by distraction and then splint it. The equipment is simple
and foolproof, easily handled by any orthopedic surgeon familiar
with modern procedures.
* * * * *